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La endocitosis vesicular requiere una hidrólisis GTP dependiente de dinamina en una sinapsis rápida del SNC
Takayuki Yamashita1, Toshihide Hige, Tomoyuki Takahashi
1Department of Neurophysiology, University of Tokyo Graduate School of Medicine, Tokyo 113-0033, Japan.
Science (New York, N.Y.)
|January 8, 2005
Resumen
La dinamina-1 es esencial para la endocitosis vesicular en el cáliz de la sinapsis Held. Este estudio muestra que la actividad de la GTPasa de la dinamina-1 es crucial para el reciclaje de las vesículas sinápticas después de la liberación del neurotransmisor.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Biología celular Biología celular.
- La transmisión sináptica es la transmisión sináptica.
Sus antecedentes:
- La endocitosis vesicular es crítica para mantener la función sináptica mediante el reciclaje de las vesículas sinápticas después de la exocitosis.
- Los mecanismos moleculares subyacentes a la endocitosis en las sinapsis rápidas del sistema nervioso central (SNC) aún no se comprenden por completo.
Objetivo del estudio:
- Para investigar la dependencia molecular de la endocitosis vesicular en el cáliz de Held terminal.
- Para determinar el papel de la dinamina-1 en la vía endocítica en esta sinapsis.
Principales métodos:
- Las mediciones de capacitancia se utilizaron para monitorear la dinámica de la membrana en el cáliz del terminal de Held en rebanadas del tronco cerebral.
- La toxina botulínica E se utilizó para investigar el mecanismo de "besar y huir".
- La carga presináptica con GTPgS o el péptido de dominio rico en prolina de la dinamina-1 se empleó para inhibir la función de la dinamina-1.
Principales resultados:
- Se descubrió que el transiente de capacidad rápida, previamente sugerido como "besar y huir", era independiente de la liberación del transmisor.
- El cambio de capacitancia relacionado con la liberación se descompuso con una constante de tiempo endocitótico de 10-25 segundos.
- La inhibición de la función de la dinamina-1 por GTPgS o el péptido abolió la endocitosis, lo que lleva a una reducción dependiente del uso de la exocitosis.
Conclusiones:
- La dinamina-1 es indispensable para la endocitosis vesicular en el cáliz de la sinapsis Held.
- La actividad de la guanosina trifosfatasa de la dinamina-1 es crucial para el proceso endocítico.
- Estos hallazgos resaltan la importancia de la dinamina-1 en el reciclaje de las vesículas sinápticas en las sinapsis rápidas del SNC.
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